MedSchool: Ace Your OSCEsThe Medical Company
GET - On the App Store
Lower Limb Neuro

Lower Limb Peripheral Mononeuropathy



  • Peripheral mononeuropathy is a type of peripheral neuropathy affecting a single peripheral nerve.
    • Causes of Peripheral Mononeuropathy

    • Compression (particularly carpal tunnel and ulnar tunnel) - prolonged pressure, hereditary neuropathy with liability to pressure palsies (HNPP)
    • Trauma - blunt trauma, penetrating injury (e.g. knife, gunshot, glass)
    • Nerve ischaemia - trauma, thromboembolism, diabetes, atherosclerosis, excessive tourniquet use
    • Radiation injury
    • Peripheral Nerves of the Lower Limb

    • NerveSensoryMotor
      SciaticNilKnee flexion
      Lateral CutaneousLateral thighNil
      Common PeronealLateral calf
      Dorsum of the foot
      Toe extension
      Posterior TibialPlantar aspect of the footPlantar flexion
      FemoralAnterior thigh
      Medial calf
      Hip flexion
      Knee extension

Sciatic Nerve Palsy

  • The sciatic nerve branches into the tibial nerve and the common peroneal nerve, and as such palsy of the sciatic nerve will affect both of these nerves
    • Signs of Sciatic Nerve Palsy

    • Sciatic nerve proper - weakness of knee extension
    • Common peroneal nerve - sensory loss over the lateral calf and dorsum of the foot; weakness of dorsiflexion, foot eversion and toe extension
    • Posterior tibial nerve - sensory loss over the plantar aspect of the foot; weakness of plantar flexion
    • Causes of Sciatic Nerve Palsy

    • Direct trauma
    • Stretch injury
    • Hip dislocation
    • Intramuscular injections incorrectly performed in the gluteal region
    • Total hip replacement

Lateral Cutaneous Nerve Palsy

  • Lateral cutaneous nerve palsy is also known as meralgia paraesthetica.
    • Signs of Lateral Cutaneous Nerve Palsy

    • Sensory loss over the lateral thigh
    • No motor manifestations
    • Causes of Lateral Cutaneous Nerve Palsy

    • Occurs due to entrapment of the lateral cutaneous nerve beneath the inguinal ligament.

    • Increased intra-abdominal pressure - obesity, pregnancy
    • Tight clothing - particularly belts and suspenders

Common Peroneal Nerve Palsy

    • Signs of Common Peroneal Nerve Palsy

    • Foot drop
    • Weakness of ankle dorsiflexion and foot eversion
    • Sensory loss over the dorsum of the foot and lateral shin
    • Causes of Common Peroneal Nerve Palsy

    • Trauma - tibial or fibular fracture, ligamentous injury, nerve injury during surgery
    • Compression - tight casts, positioning during surgery, prolonged bed rest

Posterior Tibial Nerve Palsy

    • Signs of Posterior Tibial Nerve Palsy

    • Weakness of ankle plantar flexion
    • Sensory loss over the plantar aspect of the foot
    • Positive tinel’s sign over the nerve posterior to the medial malleolus
    • Causes of Posterior Tibial Nerve Palsy

    • Tarsal tunnel syndrome - entrapment within the tarsal tunnel posterior to the medial malleolus
    • Distal tibial fracture

Femoral Nerve Palsy

    • Signs of Femoral Nerve Palsy

    • Wasting of the quadriceps
    • Weakness of hip flexion and knee extension
    • Reduced / absent patellar reflexes
    • Reduced sensation over the anterior thigh and medial calf
    • Causes of Femoral Nerve Palsy

    • Hanging leg syndrome - prolonged hanging of a leg over an edge e.g. off a mattress
    • Total hip replacement
    • Stretch injury
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now


 Azhary H, Farooq MU, Bhanushali M, Majid A, Kassab MY. Peripheral neuropathy: differential diagnosis and management. Am Fam Physician. 2010 Apr 1;81(7):887-92. Baima J, Krivickas L. Evaluation and treatment of peroneal neuropathy. Current reviews in musculoskeletal medicine. 2008 Jun 1;1(2):147-53. Benny BV, Nagpal AS, Singh P, Smuck M. Vascular causes of radiculopathy: a literature review. The spine journal. 2011 Jan 1;11(1):73-85. Biering-Sorensen F, Nielsen JB, Klinge K. Spasticity-assessment: a review. Spinal Cord. 2006;44:708-722. Boyraz I, Uysal H, Koc B, Sarman H. Clonus: definition, mechanism, treatment. Med Glas. 2015;12:19-26. Campbell WW. Evaluation and management of peripheral nerve injury. Clinical neurophysiology. 2008 Sep 1;119(9):1951-65. Fuller G. Focal peripheral neuropathies. Journal of Neurology, Neurosurgery & Psychiatry. 2003 Jun 1;74(suppl 2):ii20-4. Hoshino C, Koga D, Koyano G, Yamauchi Y, Sakai T, Okawa A, Jinno T. Femoral nerve palsy following primary total hip arthroplasty with the direct anterior approach. PloS one. 2019 May 20;14(5):e0217068. Johnston SC, Hauser SL. The beautiful and ethereal neurological exam: An appeal for research. Ann Neurol. 2011;70:A9-A10. Khare S, Seth D. Lhermitte's Sign: The current status. Annals of Indian Academy of Neurology. 2015 Apr;18(2):154. Khasnis A, Gokula RM. Romberg's test. J Postgrad Med. 2003;49:169.
Lee F, Lamont P, Powell A, Paul V, Stoyanov N. Cardiac Manifestations of Myotonic Dystrophy-Complexities in Diagnosis and Management. Heart, Lung and Circulation. 2017 Jan 1;26:S305.
 Lozsadi D. Myoclonus: a pragmatic approach. Practical Neurology [serial online]. August 2012;12(4):215-224. Menorca RM, Fussell TS, Elfar JC. Peripheral nerve trauma: mechanisms of injury and recovery. Hand clinics. 2013 Aug;29(3):317. Miller TM. Differential diagnosis of myotonic disorders. Muscle & nerve. 2008 Mar 1;37(3):293-9. Moore AE, Stringer MD. Iatrogenic femoral nerve injury: a systematic review. Surgical and Radiologic Anatomy. 2011 Oct 1;33(8):649-58. Nowak DD, Lee JK, Gelb DE, Poelstra KA, Ludwig SC. Central cord syndrome. JAAOS-Journal of the American Academy of Orthopaedic Surgeons. 2009 Dec 1;17(12):756-65. Pearce JMS. Dystonia. European Neurology. 2005; 53: 151-152. Plessen K. Tic disorders and Tourette's syndrome. European Child & Adolescent Psychiatry [serial online]. February 2, 2013;22:55-60. Reynolds J, Stavros K. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): clinical features, diagnosis, and current treatment strategies. Rhode Island Medical Journal. 2016 Dec 1;99(12):32. Robottom BJ, Factor SA, Weiner WJ. Movement Disorders Emergencies Part 2: Hyperkinetic Disorders. Arch Neurol. 2011;68:719-724. Rodriguez-Garcia PL, Rodriguez-Pupo L, Rodriguez-Garcia D. Clinical techniques for use in neurological physical examinations. I. General organisation, cranial and peripheral spinal nerves. Rev Neurol. 2004 Oct; 39(8): 757-66. Skogseid I. Dystonia--new advances in classification, genetics, pathophysiology and treatment. Acta Neurologica Scandinavica. Supplementum [serial online]. 2014;(198):13-19. Smaga S. Tremor. American Family Physician. 2003; 68:1545. Statland JM, Barohn RJ, McVey AL, Katz JS, Dimachkie MM. Patterns of weakness, classification of motor neuron disease, and clinical diagnosis of sporadic amyotrophic lateral sclerosis. Neurologic clinics. 2015 Nov 1;33(4):735-48. Stevens F, Weerkamp NJ, Cals JW. Foot drop. BMJ: British Medical Journal (Online). 2015 Apr 27;350.
Stewart JD. Foot drop: where, why and what to do?. Practical neurology. 2008 Jun 1;8(3):158-69.
 Suresh E, Wimalaratna S. Proximal myopathy: diagnostic approach and initial management. Postgraduate medical journal. 2013 Aug 1;89(1054):470-7. Tarsy D, Simon DK. Dystonia. The New England Journal of Medicine. 2006; 355: 818-829. Triplett JD, Robertson A, Yiannikas C. Compressive Lateral Femoral Cutaneous Neuropathy Secondary to Sartorius Muscle Fibrosis. JAMA neurology. 2019 Jan 1;76(1):109-10. Turner MR, Talbot K. Mimics and chameleons in motor neurone disease. Practical neurology. 2013 Jun 1;13(3):153-64. Valergakis FE. Cervical spondylosis: most common cause of position and vibratory sense loss. Geriatrics.1976; 31:51. Van Gijn J. The Babinski reflex. Postgrad Med J. 1995;71:645-648. Walker RH. Chorea. CONTINUUM: Lifelong Learning in Neurology. 2013;19:1242-1263. Walker RH. O.061 Choreas - phenomenology and differential diagnosis. Parkinsonism and Related Disorders. 2009;15:S16-S16. Webb CW. Mnemonic: Decorticate vs Decerebrate. Annals of Emergency Medicine. 1981 Jan; 10(1): 68. Wenninger S, Montagnese F, Schoser B. Core clinical phenotypes in myotonic dystrophies. Frontiers in neurology. 2018;9:303. Wild EJ, Tabrizi SJ. The differential diagnosis of chorea. Practical neurology. 2007;7:360-373. Wiles CM. Introducing neurological examination for medical undergraduates: how I do it. Pract Neurol. 2013 Feb; 13(1): 49-50.